/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.druid.indexing.overlord;

import com.google.common.base.CharMatcher;
import com.google.common.base.Preconditions;
import com.google.common.base.Splitter;

import java.util.Iterator;

/**
 * Make an iterable of space delimited strings... unless there are quotes, which it preserves
 */
public class QuotableWhiteSpaceSplitter implements Iterable<String>
{
  private final String string;

  public QuotableWhiteSpaceSplitter(String string)
  {
    this.string = Preconditions.checkNotNull(string);
  }

  @Override
  public Iterator<String> iterator()
  {
    return Splitter.on(
        new CharMatcher()
        {
          private boolean inQuotes = false;

          @Override
          public boolean matches(char c)
          {
            if ('"' == c) {
              inQuotes = !inQuotes;
            }
            if (inQuotes) {
              return false;
            }
            return CharMatcher.breakingWhitespace().matches(c);
          }
        }
    ).omitEmptyStrings().split(string).iterator();
  }
}
